Measuring Success of Rehabilitation
The howler monkey releases are part of an endangered species reintroduction programme with an exceptionally high success rate of 95% post-release survival through the first year, and first and second-generation babies born in the wild in a flourishing new population at the release site in Fireburn, part of Belize’s northeastern biological corridor. How do we know this?
We invest in post-release monitoring to ensure we can track howler monkeys from the moment of release for the first two months - almost every day. We watch as they establish their territories and settle in to being wild monkeys, and use the information we learn to inform our next releases. We then continue to check in on them to ensure they are doing well during their first year. After the initial five years, we assessed the population, with 85% of released monkeys being identified and doing well (Tricone, 2015) - and a further two turning up after the survey, taking the total to 95% survival in the first five years. A ten year survey was planned, and postponed as a result of Covid-19, but we are now back in the field, ready to start the census of Fireburn howler monkeys, identifying the troops and plotting their territories.
Alisha Huotari, from the University of Salford, has joined us to lead the seven months of field survey work as part of her Masters Thesis. No stranger to Wildtracks, she has volunteered with the endangered Yucatan black howler monkeys at the Primate Rehabilitation Centre. She shares with us her initial thoughts as she starts the field work.
This past week kicked off the first of many survey trips to Fireburn, the main release site for the Yucatan black howler monkeys that have passed through the primate rehabilitation process here at Wildtracks. Over the next seven months, I’m going to be assessing the success of the rehabilitation and reintroduction of howler monkeys into the Fireburn Forest, part of the North-Eastern Biological Corridor, here in Belize. Wildtracks has been releasing howler monkeys into the Fireburn Forests since 2011 through a carefully designed rehabilitation-reintroduction process, with 75 howler monkeys introduced into the area to date. Previous estimates of the population suggest there are between 150 and 200 individuals. I am partnering with an experienced primate tracker, and will be in and out of the rainforest counting, tracking, and collecting data on the growing population.
This familiarization visit was about getting to grips with forest life. I have started to learn key tracking skills from the Wildtracks post Release Tracking Team, the basics of keeping safe in the tropical forest as well as testing out data collection. Before leaving, I was nervous and completely unsure of what to expect, but after months of talking about it and planning, it has happened. Well, what a welcome the howlers gave us! In the 5 days we spent in the forest we found 3 troops of howler monkeys, a total of 18 individuals. Hopefully many more will be found in the upcoming trips!
The forest is full of life…aside from monkeys, we spotted some huge tarantulas, a coati that I thought was a monkey (I’m going to have to work on my arboreal mammal identification!) and a glimpse of the beak of a toucan. This whirlwind of an experience has already taught me so much - including that taking pictures of monkeys is a lot harder than I was expecting! I’ve worked with some of these monkeys when they were in rehabilitation, as a Wildtracks Volunteer in the past - seeing and hearing these monkeys calling in the wild is better than I could have ever imagined! In so many ways it feels like I was always meant to be doing this and I can’t help thinking that little me would be so proud. I’m very much looking forward to seeing what the next year brings!
Wildtracks operates under a Memorandum of Understanding with the Belize Forest Department for the Primate Rehabilitation Centre, and under a research permit for the 10 year assessment.